What I've learnt (so far)
To change my mind according to reason. To welcome evidence, uncomfortable or not. That Occam’s Razor is fundamental. That consistency is fundamental and hard. To listen carefully, but to take nothing on authority. That neither truth nor good is established by vote. To admit mistakes swiftly and sincerely, to others and myself. To appreciate reasonable people willing to argue opposing views. That in ignorance there is no shame; in unwillingness to learn, plenty.
That religion and superstition are dead ends.
That most things are outside my control and that that is all right. That the past can not be changed and to move on. To accept that death will come, often without warning, for me and others. That security is better achieved through resilience than protection. That in the choice between liberty and safety, only the former is sustainable.
To strive to better myself.
That character is the result of consistently acting according to sensible values. To work on what has a chance of making things better. To optimise over long time-frames. That self-control is the foundation of much that is good. That anyone can change, but those who think they can’t don’t. To try to treat people right, regardless of their ability to do me harm or good. That politeness is better than the alternative.
That I have a long way to go.
That happiness is not found in objects, circumstances, or the opinions of others; it is the result of how I think and spend my time. To enjoy pleasures, but to fight hedonistic adaptation. That possessions are a burden unless they promote focus or save time doing what is good.
But above all: to change my mind according to reason.